Method of and apparatus for assembling door handle

ABSTRACT

A handle case and a handle which are substantially assembled are clamped on a pallet with respective first and second clamping means on the pallet, and the pallet is conveyed along a looped conveyor. The handle case and the handle are connected operatively to each other with a hinge in a first assembling station disposed alongside of the conveyor. Then, the pallet is conveyed successively through other assembling stations disposed along the conveyor to install other door handle components on the handle case and the handle in the other assembling stations.

This application is a divisional of copending application Ser. No.07/334,155, filed on Apr. 6, 1989 U.S. Pat. No. 4,967,471.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of and an apparatus forassembling a door handle, and more particularly to a method of and anapparatus for assembling a door handle completely automatically fromdoor handle components in a system for producing door handles to beinstalled on the outer surface of automotive door panels.

2. Description of Related Art

When getting into an automobile, a door of the automobile is opened bygripping a door handle installed on the outer surface of the panel ofthe door. One known door handle for use on an automobile door isillustrated in FIGS. 1 and 2 of the accompanying drawings. FIG. 1 showsthe various components of a door handle assembly 2, and FIG. 2illustrates the door handle assembly 2 as it is completed.

The door handle assembly 2 basically comprises a handle case 4 and ahandle 6, and also includes various other accessory parts. The handle 6is angularly movably coupled to the handle case 4 by means of hinge pins8a, 8b. More specificaly, the handle 6 includes a hinge lever 10aconnected to support arms 12a, 12b of the handle case 4 by the hinge pin8a, and another hinge lever 10b connected to support arms 12c, 12d ofthe handle base 4 by the hinge pin 8b. Torsion coil springs 14a, 14bcoact respectively between the support arm 12b and the hinge lever 10aand between the support arm 12c and the hinge lever 10b for normallyholding the handle 6 against the handle case 4 when the handle 6 isassembled in the handle case 4. Stoppers 16 of rubber are mounted in thehandle case 4 for preventing the handle 6 from directly hitting thehandle case 4 to protect the handle case 4.

The handle case 4 has an integral protective member 18 projectinginwardly from the inner surface of a corner of the handle case 4. Theprotective member 18 serves to surround a lock in a door to protect thesame when the door handle assembly 2 is installed on the door. A keyguard assembly 20 is mounted in the protective member 18. The key guardassembly 20 comprises an annular gasket 22 and a gasket cap 24 by whichthe gasket 22 is fixed to the outer end of the protective member 18 andprotected from damage. For attaching the key guard assembly 20, thegasket cap 24 and the gasket 22 are axially combined together into thekey guard assembly 20, and then tongues 28a, 28b on the gasket cap 24are inserted respectively into grooves 26a, 26b defined in the handlecase 4 and bent over by staking into firm engagement with the handlecase 4.

A case gasket 30 is interposed between the handle case 4 and a doorpanel 31 to provide a seal therebetween. The handle case 4 has aplurality of protrusions 32 on an outer peripheral flange thereof whichare inserted into respective holes defined in the case gasket 30 andsubsequently deformed by staking to hold the case gasket 30 in position.A bushing 34 is inserted in the hinge lever 10a and coupled to themechanism of the lock in the door.

As described above, the door handle assembly 2 is comprised of thehandle case 4, the handle 6, the hinge pins a, 8b, the coil springs 14a,14b, and other small components. To assemble the door handle assembly 2,the small parts such as the key guard assembly 20, the stoppers 16, andthe case gasket 30 are first installed on the handle case 4, and thenthe handle 6 and the handle case 4 are coupled to each other by the coilsprings 14a, 14b and the hinge pins 8a, 8b.

The above assembling procedure is necessitated for the followingreasons: For putting the key guard assembly into the handle case 4,three assembling steps are required: First, the gasket 22 and the gasketcap 24 are combined into the key guard assembly 20. Then, the tongues a,28b on the gasket cap 24 are inserted respectively into the grooves 26a,26b in the handle case 4. Finally, the tongues 28a, 28b are bentradially inwardly by a staking tool to fasten the key guard assembly 20to the handle case 4. The key guard assembly 20 has to be inserted intothe handle case 4 from its face side. To attach the case gasket 30 tothe handle case 4, the handle case 4 is reversed or turned over andfixed to a suitable jig. Then, the case gasket 30 is mounted on thehandle case 4 in engagement with the protrusions 32, which arethereafter deformed by a hand tool to fasten the case gasket 30 to thehandle case 4. Since the handle case 4 must be kept in one position forinstalling one component, and then reversed into another position forinstalling another component, it is necessary that the small parts beattached to the handle case 4 at first and then the handle case 4 andthe handle 6 be coupled to each other.

As described above, it is current practice to assemble the door handleassembly 2 only with manual labor, using jigs and tools suitable for usein respective assembling steps.

However, the manual assembling process is disadvantageous in that theassembling capability is limited and the efficiency depends on the skillof the worker who assembles the components. If the efficiency is to beincreased according to the present manual method, the cost of skillfulmanual labor will also be increased, and so will the cost of manufactureas personal expenses have a large share in the overall cost these days.Therefore, there has been a strong demand in the art for a fullyautomated process for assembling door handles.

SUMMARY OF THE INVENTION

It is a general object of the present invention to provide a method ofand an apparatus for assembling a door handle completely automaticallyin a process ranging from the supply of door handle components to theassembly of these door handle components, without any manualintervention, so that the door handle can be assembled highlyefficiently.

Another object of the present invention is to provide a method ofassembling a door handle, comprising the steps of: clamping a handlecase and a handle which are substantially assembled on a pallet withrespective first and second clamping means on said pallet; conveyingsaid pallet along a looped conveyor; connecting said handle case andsaid handle operatively to each other with hinge means in a firstassembling station disposed alongside of said conveyor; and thereafterconveying said pallet successively through other assembling stationsdisposed along said conveyor to install other door handle components onsaid handle case and said handle in said other assembling stations.

Still another object of the present invention is to provide a method ofassembling a door handle, wherein said hinge means comprises a pair offirst and second coil springs and a pair of first and second hinge pins,further including the steps of: installing said first coil spring andsaid second hinge pin on said handle case and said handle in said firstassembling station; and thereafter installing said second coil springand said second hinge pin on said handle case and said handle in a nextassembling station.

Still another object of the present invention is to provide a method ofassembling a door handle, wherein said other door handle componentsinclude a stopper to be installed in one of said other assemblingstations, further including the steps of: releasing said first clampingmeans to unclamp said handle case while clamping said handle to saidpallet with said second clamping means in one of said other assemblingstations; thereafter, turning said handle case on said handle in saidone of the other assembling stations; and inserting the stopper intosaid handle case in said one of the other assembling stations.

Yet another object of the present invention is to provide an apparatusfor assembling a door handle primarily from a handle case and a handlein an assembling station disposed alongside of a looped conveyor, saidapparatus comprising: means for clamping a handle case and a handlewhich are substantially assembled on a pallet; pin hole registeringmeans for inserting a guide pin into pin holes defined respectively insaid handle case and said handle to register said pin holes with eachother; pin inserting means for receiving a supplied hinge pin andinserting the hinge pin through said pin holes in coaction with said pinhole registering means; and positioning means for positioning a hingelever of said handle.

Yet still another object of the present invention is to provide anapparatus for assembling a door handle, wherein said pin holeregistering means includes a table movable back and forth in a directionin which said hinge pin is inserted through said pin holes, and arotative drive source mounted on said table, said guide pin beingmounted on said table and rotatable about its own axis by said rotativedrive source.

A further object of the present invention is to provide an apparatus forassembling a door handle, wherein said pin inserting means includes atable movable back and forth in a first direction in which said hingepin is inserted through said pin holes, chuck means mounted on saidtable for holding the hinge pin, said chuck means being movable back andforth in a second direction transverse to said first direction, and aplate member mounted on said table for holding a rear portion of saidhinge pin when the hinge pin is inserted through said pin holes, saidplate member being arranged in said second direction.

A yet further object of the present invention is to provide an apparatusfor assembling a door handle, further including a first cylinder formoving said pin hole registering means back and forth, a second cylinderfor moving said pin inserting means back and forth, and an auxiliarycylinder interconnecting said first and second cylinders.

Another object of the present invention is to provide an apparatus forassembing a door handle primarily from a handle case and a handle in anassembling station disposed alongside of a looped conveyor, saidapparatus comprising: means for clamping a handle case and a handlewhich are substantially assembled on a pallet; stopper supply means forreceiving a stopper in a vertically movable socket and moving saidstopper into engagement with a needle on a robot wrist; and a jig fortemporarily unclamping said handle case and turning said handle casewhen said stopper is to be installed on said handle case.

Still another object of the present invention is to provide an apparatusfor assembling a door handle, wherein said jig includes a verticalsurface plate, a clamp release lever movable back and forth by a firstcylinder for engaging a clamping member on said pallet, and a hand forengaging said handle case and turning the handle case with a secondcylinder.

Still another object of the present invention is to provide an apparatusfor assembling a door handle, wherein said stopper supply means includesa positioning plate for engaging a bar mounted on said robot wrist andhaving said needle on a distal end thereof for holding said bar in apredetermined position when said stopper engages said needle.

Yet another object of the present invention is to provide a pallet fordelivering a handle case and a handle on a looped conveyor while fixingsaid handle case and said handle in position, said pallet comprising:first clamping means for clamping said handle case while holding saidhandle case and said handle in a substantially assembled relationship;and second clamping means for clamping said handle.

Yet still another object of the present invention is to provide a palletfurther including a body and a plurality of positioning members mountedon a peripheral edge of said body for holding said handle case againstdisplacement, said first clamping means being disposed on a side of saidbody for clamping said handle case, and said second clamping means beingdisposed on a center of said body for clamping said handle.

A further object of the present invention is to provide a pallet whereinsaid first clamping means comprises a pair of clamping members angularlymovably mounted on said body and normally urged by respective coilsprings to cause distal ends thereof to engage said handle case.

A yet further object of the present invention is to provide a palletwherein said second clamping means comprises a clamp lever for clampingsaid handle, and a pair of push rods normally urged by respective coilsprings having different resilient forces to engage said clamp lever inconfronting relation to each other.

The above and other objects, features and advantages of the presentinvention will become more apparent from the following description whentaken in conjunction with the accompanying drawings in which a preferredembodiment of the present invention is shown by way of illustrativeexample.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a door handle to be assembledby a door handle assembling method and apparatus according to thepresent invention;

FIG. 2 is a perspective view of the completed door handle mounted on adoor panel;

FIG. 3 is a schematic plan view of an assembling system incorporatingthe door handle assembling apparatus according to the present invention;

FIG. 4 is a perspective view of a pallet with a handle case and a handlefixed to the pallet;

FIG. 5 is a cross-sectional view of the pallet;

FIG. 6 is a perspective view of a handling robot installed in eachassembling station in the assembling system;

FIG. 7 is a perspective view of a pin inserting device in a secondassembling station;

FIG. 8 is a plan view of the pin inserting device prior to the insertionof a hinge pin;

FIG. 9 is a perspective view of the pin inserting device at the time ofinserting a guide pin;

FIG. 10 is a plan view of the pin inserting device at the time ofinserting the hinge pin;

FIG. 11 is a side elevational view, partly in cross section, of the pininserting device;

FIG. 12 is a side elevational view of a supply device for supplying acase gasket to a handling robot in a fifth assembling station;

FIG. 13 is a perspective view of a case gasket applicator in the fifthassembling station;

FIG. 14 is a perspective view of a gripping mechanism in a pickup unit;

FIG. 15 is a perspective view of an alignment unit for correcting theshape of a case gasket;

FIG. 16 is a side elevational view, partly in cross section, of thealignment unit;

FIG. 17 is a cross-sectional view of the alignment unit;

FIG. 18 is a perspective view of an end effector of the handling robot;

FIG. 19 is a side elevational view of the end effector;

FIG. 20 is a perspective view of an assisting jig of the case gasketapplicator;

FIG. 21 is a side elevational view of the assisting jig;

FIG. 22 is a perspective view of a device for fixing a case gasket in asixth assembling station;

FIG. 23 is a side elevational view of a device for staking hinge pins ina seventh assembling station;

FIG. 24 is a perspective view of a device for superposing key guardassembly components in a fifth assembling station;

FIGS. 25 through 27 are cross-sectional views showing an operationsequence of a superposing mechanism in the superposing device;

FIG. 28 is a perspective view of a handling robot in an eighthassembling station;

FIG. 29 is a perspective view of an end effector of the handling robotillustrated in FIG. 28;

FIGS. 30a and 30b are cross-sectional views illustrating the manner inwhich the end effector of FIG. 29 operates;

FIG. 31 is a perspective view of a stopper supply device and a handlingrobot end effector in a tenth assembling station;

FIG. 32 is a perspective view of a jig in the tenth assembling station;and

FIG. 33 is a side elevational view of the jig shown in FIG. 32.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

First, an assembling system incorporating a door handle assemblingapparatus according to the present invention will be described.

FIG. 3 shows an assembling system 40 in plan which includes firstthrough tenth assembling stations 41 through 50. Door handle componentsare successively assembled in the assembling stations 41 through 50, anda door handle is completed in the tenth assembling station 50. The doorhandle to be assembled by the door handle assembling apparatus isidentical to the door handle assembly 2 shown in FIGS. 1 and 2. The doorhandle components are denoted by identical reference numerals employedin FIGS. 1 and 2, and will not be described in detail. A door handlethat can be assembled by the door handle assembling apparatus is notlimited to the illustrated design, but may be of another construction.

Assembling steps to be carried out in the respective first through tenthassembling stations 41 through 50 are briefly summarized in thefollowing Table 1:

    ______________________________________                                        Station        Operation                                                      ______________________________________                                        First station 41                                                                             Fixing of workpieces                                           Second station 42                                                                            Installation of hinge pins 8a,                                                8b and coil springs 14a, 14b                                   Third station 43                                                                             Installation of hinge pins 8a,                                                8b and coil springs 14a, 14b                                   Fourth station 44                                                                            Standby operator                                               Fifth station 45                                                                             Setting of case gasket 30                                      Sixth station 46                                                                             Fixing of case gasket 30                                       Seventh station 47                                                                           Staking of hinge pins 8a, 8b                                   Eighth station 48                                                                            Mounting of key quard assembly                                                20                                                             Ninth station 49                                                                             Insertion of bushing 34                                        Tenth station 50                                                                             Mounting of stopper 16                                         ______________________________________                                    

The first through tenth assembling stations 41 through 50 are disposedalongside of a looped conveyor 52. The conveyor 52 carries and conveys anumber of pallets on which workpieces are fixedly mounted. FIGS. 4 and 5shows in detail such a pallet 54 on which workpieces, such as, a handlecase 4 and a handle 6, are clamped. The pallet 54 has a clamping meansfor clamping the handle case 4 and another clamping means for clampingthe handle 6. The handle case 4 and the handle 6 are fixed to the pallet54 while they are substantially assembled together, as shown in FIG. 4.

The pallet 54 includes a pallet base 56 having a pair of horizontalnotches 58a, 58b defined in opposite sides thereof for receiving dogchucks (not shown) disposed in each of the assembling stations alongsideof the conveyor 52 to stop the pallet 54 in position at each assemblingposition. One of the sides of the pallet base 56 has a vertical notch 60defined therein across the horizontal notch 58a, for example. The pallet54 can be positioned more accurately in each assembling station byengaging another dog chuck in the vertical notch 60.

A jig body 62 is fixedly mounted on the upper surface of the pallet base56. The jig body 62 includes a first block 64 in the shape of arectangular parallelepiped and a second block 66 disposed substantiallycentrally on the upper surface of the first block 64. Positioningmembers 68a through 68d are mounted on the upper surface of the secondblock 66 for engaging peripheral edges of the handle case 4 to positionthe handle case 4 against unwanted displacement. The first clampingmeans for clamping the handle case 4 is disposed on one side of thesecond block 66. More specifically, the first clamping means includes apair of clamping members 70a, 70b angularly movably attached to thesecond block 66 by means of respective pins 72a, 72b. Compression coilsprings 74a, 74b housed in the second block 66 engage the lower ends ofthe clamping members 70a, 70b, respectively, for normally urging theclamping members 70a, gers thereof to hold the handle case 4 downagainst the second block 66 (see FIG. 5).

The second clamping means for clamping the handle 6 is positionedsubstantially centrally in the jig body 62. More specifically, asillustrated in FIG. 5, the second clamping means includes a verticallyextending hole 76 defined through the second block 66, and a clamp lever80 disposed in the hole 76 and swingably supported by a pin 78. Thefirst block 64 has a pair of horizontal holes 82a, 82b defined thereinand communicating with the vertical hole 76, the holes 82a, 82bextending from the opposite sides of the first block 64 toward eachother. Push rods 86a, 86b are disposed respectively in the holes 82a,82b and have respective distal ends engaging the lower end of the clamplever 80 in confronting relation under the resiliency of respective coilsprings 84a, 84b disposed in the holes 82a, 82b around the push rods86a, 86b. The coil spring 84b produces larger resilient forces than thecoil spring 84a, so that the push rod 86b turns the clamp lever 80 aboutthe pin 78 in the direction of the arrow A at all times against the biasof the coil spring 84a. Therefore, the handle 6 is held in position by abent upper distal end of the clamp lever 80. A clamp release rod 88engages the outer end of the push rod 86a. By bushing the clamp releaserod 88, the clamp lever 80 is turned about the pin 78 in the directionof the arrow B to unclamp the handle 6.

The structure and operation of devices in the respective first throughtenth assembling stations 41 through 50 will be described below inrelation to assembling steps to be carried out in the respectiveassembling stations.

The first assembling station 41 operates to fix the handle case 4 andthe handle 6 to the pallet 54. The operator who attends the firstassembling station 41 actuates the clamping means on the pallet 54 toclamp the handle case 4 and the handle 6 thereon in a substantiallyassembled condition as shown in FIGS. 4 and 5. More specifically, afterthe operator has put the handle case 4 and the handle 6 together, theoperator brings the handle case 4 into engagement with the positioningmembers 68a through 68d and pushes the clamp release rod 88 to turn theclamp lever 80 slightly in the direction of the arrow B, allowing thehandle 6 to be positioned below the distal end of the clamp lever 80.Then, the clamp release lever 88 is released to cause the push rod 86b,which is biased by the coil spring 84b that is stronger in resiliencythan the coil spring 84a which biases the push rod 86a, to turn theclamp lever 80 in the direction of the arrow A until the bent upper endthereof holds the handle 6 down in position. As shown in FIG. 4, thehandle case 4 is prevented from positional displacement by thepositioning members 68a through 68d, and fixed in position by the upperfingers of the clamping members 70a, 70b.

The handle case 4 and the handle 6 as they are assembled together arethus held on the pallet 54, which is delivered on the conveyor 52 to thesecond assembling station 42. According to the principles of theassembling method of the invention, the handle case 4 and the handle 6are first put together as described above, and then other accessorycomponents are installed on the handle case 4 and the handle 6.

The second and third assembling stations 42, 43 have devices forattaching hinge pins 8a, 8b and coil springs 14a, 14b to the handle case4 and the handle 6 which have been conveyed from the first assemblingstation 4 by the conveyor 52, so that the handle case 4 and the handle 6are hinged to each other. More specifically, in the second assemblingstation 42, the hinge pin 8b is inserted through the support arms 12c,12d of the handle case 4 and the hinge lever 10b of the handle 6, andthe coil spring 14b is placed in engagement with the support arm 12c andthe hinge lever 10b. In the third station 43, the hinge pin 8a isinserted through the support arms 12a, 12b of the handle case 4 and thehinge lever 10a of the handle 6, and the coil spring 14a is placed inengagement with the support arm 12b and the hinge lever 10a. Theoperation of the second assembling station 42 are thus substantially thesame as the operation of the third assembling station 43. Therefore,only the second assembling station 42 will be described below, and thoseparts of the third assembling station 43 which are identical to those ofthe second assembling station 42 are denoted at identical referencenumerals and will not be described in detail.

The second assembling station 42 includes a handling robot 90 forattaching the coil spring, and a pin inserting device 92 for insertingthe hinge pin, and additionally has a parts feeder for supplying thecoil spring and the hinge pin and a positioning mechanism forpositioning the pallet 54 in place. The parts feeder and the positioningmechanism are not illustrated in FIG. 3.

FIG. 6 shows the handling robot 90. While the handling robot 90 may beany of various industrial robots which are currently available for usein production sites, the handling robot 90 in the illustrated embodimentcomprises a known industrial robot having six axes with the number ofdegrees of freedom being 6. The handling robot 90 comprises a swivelbase 94, a first arm 96, a second base 98, and a wrist 100 mounted onthe distal end of the second arm 98. By teaching the wrist 90 through adesired path of movement, an end effector or hand mounted on the wrist100 can be displaced along the desired path.

While not illustrated in FIG. 6, a chuck mechanism for gripping the coilsprings 14a, 14b at their opposite ends is employed as the end effector.The handling robot 90 shown in FIG. 6 is also provided in each of thethird, fifth, eighth, ninth, and tenth assembling stations 43, 45, 48,49, 50. However, the handling robots 90 in these assembling stationshave end effectors designed to achieve respective operations in theassembling stations. Such end effectors will be described later on withreference to the respective assembling stations.

The pin inserting device 92 will now be described with reference toFIGS. 7 through 9.

FIG. 7 shows the pin inserting device 92 in perspective. The pininserting device 92 has a surface plate 102 mounted on a lifting andlowering mean including a drive source such as a cylinder. A guide plate104 is fixedly mounted on the surface plate 102, and first and secondslide tables 106, 108 which are slidable in the direction in which thehinge pin is inserted are fitted over the guide plate 104.

On the first slide table 106, there is disposed a pin hole registeringmeans 110 for registering the pin holes in the handle case 4 and thehandle 6 before a hinge pin is inserted and for guiding the hinge pinwhen it is inserted. A pin inserting means 112 is disposed on the secondslide table 108 for receiving a hinge pin supplied from a supply tube111 extending from the parts feeder and for inserting the received hingepin into the pin holes. A first positioning member 120 is positioned asa positioning means near the first slide table 106 for positioning thehinge lever 10b of the handle 6 so that the hinge lever 10b will not bepositionally displaced, the first positioning member 120 being axiallymovable back and forth by a first cylinder 124 of the positioning means.The other hinge lever 10a of the handle 6 is also positioned by anotherpositioning means disposed alongside of the second slide table 108 andincluding a second positioning member 126 and a second cylinder 128.

The pin hole registering means 110 on the first slide table 106comprises a rotative drive source 130 such as an electric motor, and aguide pin 132 rotatable by the motor 130 and insertable into the pinholes in the hinge lever 10b of the handle 6 and the support arms 12c,12d of the handle case 4 for registering the pin holes to permit thehinge pin to be subsequently inserted smoothly and reliably. Rotativepower from the motor 130 can be transmitted to the guide pin 132 by abelt 134 operatively coupled to the motor 130 and a gear train 136 fortransmitting the rotation from the belt 134 at a predetermined speedratio to the guide pin 132.

The pin inserting means 112 disposed on the second slide table 108comprises a slide block 140 slidable in a direction normal to thedirection of insertion of the guide pin along a guide rail 138 fixedlymounted on the second slide table 108, a drive source 142 in the form ofa cylinder 142 for moving the slide block 140 back and forth, and a pinchuck means 146 mounted on the distal end of a bent attachment arm 144extending from the slide block 140. The pin chuck means 146 is clearlyillustrated in FIG. 11. The pin chuck means 146 is composed of a pinreceiver 148 attached to the attachment arm 144, a pin gripper 150 forgripping the key-shaped distal end of the pin receiver 148 and a hingepin, and a cylinder 152 coupled to the pin gripper 150. An upstandingbearing plate 153 for backing up the hinge pin when it is inserted ismounted on the second slide table 108 parallel to the direction ofmovement of the pin chuck means 146.

The pin hole registering means 110 and the pin inserting means 112 arecoupled to each other by three cylinders. More specifically, the firstslide table 106 supports thereon an upstanding bracket 154 to whichthere is secured a first cylinder 156 for displacing the pin holeregistering means 110 along the guide plate 104. The first cylinder 156has a piston rod 158 coupled to the piston rod 162 of an auxiliarycylinder 160 through a coupling 163. The auxiliary cylinder 160 is fixedto an upstanding bracket 164 mounted on the second slide table 108. Thebracket 164 is connected to the piston rod 170 of a second cylinder 168which is affixed to a vertical plate 166 mounted on the surface plate102 for displacing the pin inserting means 112 along the guide plate104. The auxiliary cylinder 160 serves to displace the pin insertingmeans 112 while holding the pin hole registering means 110 at rest. Thepin inserting device 92 is basically constructed as described above.

The second assembling station 42 will operate as follows:

The handle case 4 and the handle 6 which are substantially put togetherare delivered by the pallet 54, which is then stopped in a predeterminedposition.

As shown in FIG. 7, the first and second positioning members 120, 126 ofthe pin inserting device 92 are moved forwardly respectively by thecylinders 124, 128 until they engage the hinge levers 10a, 10b of thehandle 6 to prevent their positional displacement (see FIG. 9). Thehinge levers 10a, 10b are held in position by the positioning members120, 126 in order to prevent the pin holes from being positionallydisplaced out of registration when the hinge pin is inserted, becausethe clamp lever 80 of the pallet 54 is biased under relatively smallresilient forces and can easily be released manually.

The handling robot 90 shown in FIG. 6 then places the coil spring 14bbetween the support arm 12c of the handle case 4 and the hinge lever 10bof the handle 6 in engagement therewith.

For inserting the hinge pin 8b into the pin holes in the support arms12c, 12d and the hinge lever 10b, the pin inserting device 92 operatesin the following manner:

In FIG. 8, the pin hole registering means 110 on the first slide table106 is moved in the direction of the arrow by contracting the piston rod158 of the first cylinder 156. At this time, the motor 130 is energizedto rotate the guide pin 132 through the belt 134 and the gear train 136while inserting the guide pin 132 into the pin holes in support arm 10band the hinge levers 12c, 12d (see also the FIG. 9). Since the guide pin132 is rotating about its own axis, it can easily be inserted into thepin holes and also remove any burrs from around the pin holes. Byinserting the guide pin 132 into the pin holes, the pin holes arebrought into complete registration with each other for allowing smoothand reliable insertion of the hinge pin.

Thereafter, the pin inserting means 112 on the second slide table 108 isoperated to insert the hinge pin 8b. The hinge pin 8b is fed underpressure through the supply tube 111 until it engages the key-shapeddistal end of the pin receiver 148 of the pin chuck means 146. At thesame time, the pin gripper 150 is lowered by the cylinder 152 of the pinchuck means 146 to grip the hinge pin 86 between the pin receiver 148and the pin gripper 150. With the hinge pin 86 thus gripped, the pinchuck means 146 is moved in its entirety in the direction of the arrow(FIG. 8) by the cylinder 142 until the gripped pin 8b reaches a positionaligned with the pin holes.

The pin inserting means 112 is then displaced by extending the pistonrod 170 of the second cylinder 168 and contracting the piston rod 162 ofthe auxiliary cylinder 160 while thus keeping the pin hole registeringmeans 110 at rest, until the hinge pin 8b abuts against the tip of theguide pin 132, as shown in FIG. 10. Since the rear end of the hinge pin8b engages the bearing or backup plate 153, the hinge pin 8b is notdislodged from the pin chuck means 146. The piston rod 170 of the secondcylinder 168 is further extended and the piston rod 158 of the firstcylinder 156 is also extended to insert the hinge pin 8b into the pinholes in the hinge lever 10b and the support arms 12c, 12d. At thistime, the guide pin 132 is retracted out of the pin holes while guidingthe hinge pin 8b. After the hinge pin 8b has been inserted, the pin holeregistering means 110 and the pin inserting means 112 are brought backto their initial positions shown in FIG. 8 in readiness for a next pinhole registering cycle and a next hinge pin inserting cycle.

After the hinge pin 8b has been installed in the second assemblingstation 42, the workpieces on the pallet 54 are delivered into the thirdassembling station 43 in which the other hinge pin 8a is inserted.Operation of the third assembling station 43 will not be described herebecause it is structurally and functionally the same as the secondassembling station 42 except that the hinge pin 8a is inserted in thedirection opposite to the direction in which the hinge pin 8b isinserted by the pin inserting device 92.

After the hinge pin inserting process in the third assembling station43, various components will be attached to the handle case 4 supportedon the pallet 54 in the successive assembling stations.

No assembling device is provided in the fourth assembling station 44.Instead, the fourth assembling station 44 is attended by a standbyoperator who carries out the operation of any of the second, third, andfifth assembling stations 42, 43, 45 in the event of a problem with thatassembling station, while the troubled assembling station is being shutoff

The fifth assembling station 45 has various devices required forattaching the case gasket 30 to the handle case 4. These various devicesof the fifth assembling station 45 include a case gasket supply device171 (FIG. 12) for supplying a case gasket to the handling robot, and acase gasket applicator 172 (FIG. 13) for attaching the supplied casegasket.

As illustrated in FIG. 12, the case gasket supply device 170 comprises agasket magazine unit 176 for delivering a stack of case gaskets 30 to aprescribed separating position, a pickup unit 178 as a feeding means forseparating one case gasket 30, at a time, from the gasket stack whichhas been delivered by the gasket magazine unit 176 and for picking upthe separated case gasket and feeding the same to a given position, andan alignment unit 180 for correcting the shape of the case gasket 30which has been picked up by the pickup unit 178.

The gasket magazine unit 176 will first be described below. The gasketmagazine unit 176 includes a drive mechanism for successivelycirculating a plurality of magazine racks 182 in a loop. Each of themagazine racks 182 comprises a magazine disc 184 and two bars 186a, 186bfixed to the magazine disc 184. Several tens of case gaskets 30 aresupported and hung on the bars 186a, 186b. The magazine racks 182 aresuccessively circulated in one direction while being kept at a constantangular position at all times by a parallel-link mechanism so that thecase gaskets 30 are vertically suspended.

The pickup unit 178 is constructed as follows: The pickup unit 178includes an upstanding frame 188 mounted on the floor and supporting aunit body 190 which is vertically movable by a cylinder 189 mounted onthe frame 188. The unit body 190 is slightly tilted with respect to ahorizontal plane and includes a ball screw 194 which is rotatable aboutits own axis by a motor 192. A gripping mechanism 196 for picking upcase gaskets 30 one by one is threaded over the ball screw 194, and ismovable along a guide bar 197 parallel to the ball screw 194 by the ballscrew 194 driven by the motor 192.

The gripping mechanism 196 is illustrated in detail in FIG. 14. Agripping member 202 especially designed for gripping a case gasket 30 isfixed to a bracket 200 mounted on a rotatable shaft 198 coupled to amotor (not shown). The gripping member 202 has a slot 204 definedtherein for engaging a case gasket 30. A gripping lever 206 is swingablysupported on the gripping member 202 by means of a pin 208, and aseparator 210 is attached to the distal end of the gripping lever 206.The other end of the gripping lever 206 is operatively coupled via alink 212 to a piston rod 214a extending from a cylinder 214 serving as adrive source.

FIG. 15 shows in detail the alignment unit 180 for correcting the shapeof the case gasket 30. FIG. 16 also shows the alignment unit 180 in sideelevation, partly in cross section, and FIG. 17 shows the alignment unit180 in cross section.

As shown in FIGS. 15 and 16, the alignment unit 180 is mounted on ahorizontally extending support beam 216 mounted on the upper distant endof an upstanding frame 214 on the floor. The alignment unit 180 includesa first plate 218 on which four substantially cylindrical gaskettensioning members 220a through 220d are tiltably mounted for contactingthe respective inner surfaces of the four corners of a case gasket 30.The gasket tensioning members 220a through 220d have tapered surfacesprogressively flaring toward their lower proximal ends on the firstplate 218. A second plate 222 is supported above the first plate 218 bycolumns 224a through 224d mounted on the first plate 218.

FIG. 17 clearly shows the manner in which the gasket tensioning members220a through 220d and the first plate 218 are coupled. The gaskettensioning members 220a through 220d are mounted on the first plate 218through respective flexible couplings 226a through 226d which allow thegasket tensioning members 220a through 220d to be tilted with respect tothe first plate 218 as indicated by the arrows.

Between the first and second plates 218, 222, there is disposed a slideplate 228 (clearly shown in FIG. 17) held in sliding contact with sidesof the gasket tensioning members 220a through 220d. The slide plate 228is operatively joined to a drive source or cylinder 230 through acylindrical coupling 232 for vertical dispacement. A resilient ring 233made of a resilient material such as rubber is disposed around andengages the gasket tensioning members 220a through 220d for normallyurging them into pressed engagement with the slide plate 228.

As shown in FIG. 16, a presser plate 234 for pressing a case gasket 30down against the second plate 222 is swingably, i.e., openably andclosably, disposed on one side of the second plate 222. The presserplate 234 can be opened and closed by a cylinder 236 mounted on thesupport beam 216 and having a piston rod 238 operatively connectedthrough a link 240 to a lever 242 joined to the presser plate 234.

The case gasket applicator 172 operates to set, on the handle case 4, acase gasket 30 which has been corrected in shape by the case gasketsupply device 171. As shown in FIG. 13, the case gasket applicator 172comprises a handling robot 244, and an assisting jig 246 for assistingin holding a case gasket 30 when setting the case gasket 30 on thehandle case 4 on the pallet 54.

The handling robot 244 is identical to the handling robot 90 shown inFIG. 6 except for an end effector used thereon.

FIG. 18 shows an end effector 247 mounted on the wrist 100 of thehandling robot 244. The end effector 247 includes three chuck means 248for holding the corrected case gasket 30 at three points.

The chuck means 248 are actuated by respective chuck opening and closingcylinders 254 fixed to the lower surface of a bracket 242 secured to thewrist 100. From the cylinders 254, there depend respective collet chucks256 having slits extending from cylindrical portions to conical portions258 on their lower distal ends. The cylinders 254 have piston rods towhich widening members are attached. By lowering the widening memberswith the cylinders 254, the portions of the chuck means 248 which extendfrom the distal ends of the collet chucks 256 to the conical portions258 are spread outwardly or opened to engage in holes defined in thecase gasket 30.

The end effector 247 is also shown in side elevation in FIG. 19. Asillustrated in FIG. 19, a cylinder 262 is mounted centrally on the uppersurface of the bracket 252 and has a piston rod to which there is fixeda plate 264 with a presser member 266 attached thereto for pressing acase gasket 30. Guide bars 268a, 268b are affixed to the plate 264 forguiding the presser member 266 when it is displaced by the cylinder 262.

The assisting jig 246 is shown in FIGS. 20 and 21. The assisting jig 246includes two parallel guide rails 272a, 272b attached to opposite endsof a surface plate 270 mounted on a lifting and lowering means (notshown), and sliders 274a, 274b slidably fitted over the guide rails272a, 272b and to which a pair of respective arms 276a, 276b are fixed.A clamp release lever 278 for pressing the clamping members 70a, 70b ofthe pallet 54 for unclamping the clamping members 70a, 70b is secured atits opposite ends to the distal ends of the arms 276a, 276b. The clamprelease lever 278 is movable back and forth by a cylinder 279 disposedbehind the assisting jig 246 and having a piston rod 280 coupled to theslider 274a through a joint.

A guide plate 282 is disposed on the surface plate 270 between the guiderails 272a, 272b. A gasket holding mechanism 286 is movably disposed onthe guide plate 282 and displaceable along the guide plate 282 by acylinder 284. The gasket holding mechanism 286 has a presser member 288for pressing one end of a case gasket 30 and a cylinder 290 foractuating the presser member 288. The presser member 288 is angularlymovably supported by a pin 292 and operatively coupled to a piston rod296 of the cylinder 290 through a pair of links 294a, 294b.

The fifth assembling station 45 thus constructed will operate asfollows:

As shown in FIG. 13, after the assembling steps in the second and thirdassembling stations 42, 43 have been completed, the pallet 54 isdelivered to the fifth assembling station 45 by the conveyor 52, andthen stopped in the fifth assembling station 45.

Prior to describing a process of mounting a case gasket 30 on the handlecase 4 on the pallet 54, operation of the case gasket supply device 171for supplying a case gasket 30 to the handling robot 244 will bedescribed.

As shown in FIG. 12, one of case gaskets 30 on one of the magazine racks182 in the gasket magazine unit 176 is separated and fed, one at a time,by the gripping mechanism 196 of the pickup unit 178. More specifically,the cylinder 189 of the pickup unit 178 is actuated to raise the unitbody 190 to a predetermined position in which the ball screw 194 isrotated about its own axis by the motor 192 to move the grippingmechanism 196 forwardly (to the right in FIG. 12). When the grippingmechanism 196, together with the guide bar 197 fitted in the unit body190, reaches the position indicated by the solid lines in FIG. 12, therotation of the ball screw 194 is stopped.

In the position shown in FIG. 12, the gripping mechanism 196 contacts acase gasket 30, a portion of which is fitted in the slot 204 in thegripping member 202. Since the gripping mechanism 196 horizontallyapproaches the case gasket 30 which depends vertically, the movement ofthe gripping member 202 to engage the case gasket 30 can be facilitated.Then, the cylinder 214 is operated to turn the gripping lever 206 tocause the separator 210 to separate one case gasket 30 from the othercase gaskets 30. The separated case gasket 30 is held between theseparator 210 and the gripping member 202. A non-illustrated motor isenergized to turn the gripping mechanism 196 through about 270° in thedirection of the arrow in FIG. 12 to remove the case gasket 30 from thebars 186a, 186b and to hold the case gasket 30 in a horizontal plane.With the case gasket 30 thus held, the motor 192 is energized to movethe gripping mechanism 196 forwardy into the position indicated by thetwo dot-and-dash lines in FIG. 12 for thereby setting the case gasket 30on the alignment unit 180. When the case gasket 30 is to be set on thealignment unit 180, the gripping lever 206 of the gripping mechanism 196is opened, and at the same time the gripping mechanism 196 itself isslightly lowered by the cylinder 189, thus placing the case gasket 30 onthe alignment unit 180. After all the case gaskets 30 have been fed fromone magazine rack 182, the next magazine rack 182 is moved into aposition for coaction with the gripping mechanism 196. The magazineracks 182 are thus successively intermittently moved in a loop foruninterruptedly supplying case gaskets 30.

The alignment unit 180 corrects the case gasket 30 into a flat shape.The case gasket 30 is corrected in shape since case gaskets 30 may notbe uniform in thickness and may be locally deformed for some reasons,and deformed case gaskets 30 might cause problems. Operation of thealignment unit 180 will be readily understood from FIGS. 16 and 17.

More specifically, the piston rod 238 of the cylinder 236 is extended toturn down the presser plate 234 to press the case gasket 30 against thesecond plate 222. The case gasket 30 is forcibly sandwiched between thesecond plate 222 and the presser plate 234. As shown in FIG. 17, theslide plate 228 is lowered by the cylinder 230. Since the slide plate228 has been held in abutment against the sides of the gasket tensioningmembers 220a through 220d, the downward movement of the slide plate 228causes the gasket tensioning members 220a through 220d, which engage thefour corners of the case gasket 30, to be tilted radially outwardlybecause the slide plate 228 slidably engages the downwardly flaringsurfaces of the gasket tensioning members 20a through 220d. Therefore,the case gasket 30 is radially outwardly tensioned forcibly into a flatconfiguration. Then, the presser plate 234 is lifted to allow thecorrected case gasket 30 to be fed to a next process. At this time, thecase gasket 30 remains tensioned by the gasket tensioning members 220athrough 220d, and the tensioned case gasket 30 is gripped by thehandling robot 44.

FIG. 18 shows the manner in which the case gasket 30 on the alignmentunit 180 is held by the end effector 247 mounted on the wrist 100 of thehandling robot 244. More specifically, the handling robot 244 is movedalong a learned path to enable the end effector 247 to approach the casegasket 30 on the alignment unit 180 along a predetermined path. Then,the conical portions 258 on the distal ends of the collet chucks 256 ofthe three chuck means 248, respectively, on the end effector 246 areinserted into corresponding holes defined in the case gasket 30. Thechuck opening and closing cylinders 254 are then actuated to open thecollet chucks 256, whereby the case gasket 30 is held at three pointswhile being tensioned radially outwardly. Therefore, the case gasket 30is prevented from being distorted or deformed when it is mounted on thehandle case 4.

In FIG. 13, the handling robot 244 installs the case gasket 30 on thehandle case 4 on the pallet 54 which is held at rest in the fifthassembling station 45. At this time, the assisting jig 246 for assistingthe handling robot 244 in installing the case gasket 30 operates in themanner described below with reference to FIGS. 20 and 21.

The assisting jig 246 which is disposed on a lifting and lowering means(not shown) is initially held such that the arms 276a, 276b supportingthe clamp release lever 278 are in an elevated position represented bythe two-dot-and-dash lines in FIG. 21. The lifting and lowering means isthen operated to lower the assisting jig 246 until the clamp releaselever 278 reaches a position at the same height as that of the lowerends of the clamping members 70a, 70b of the pallet 54, whereupon thedownward movement of the assisting jig 246 is stopped. Thereafter, thecylinder 279 is operated to retract the arms 276a, 276b toward theassisting jig 246 for bringing the clamp release lever 278 between thearms 276a, 276b into engagement with the clamping members 70a, 70b andturning the clamping members 70a, 70b away from the handle case 4. Theclamping members 70a, 70b are disengaged from the handle case 4 becauseif the clamping members 70a, 70b remained in engagement with theperipheral flange surface of the handle case 4, the clamp members 70a,70b would be in the way when setting the case gasket 30 on the handlecase 4.

Then, the handling robot 244 places the case gasket 30 held by the endeffector 247 on the handle case 4 on the pallet 54. At this time, inorder to reliably separate the case gasket 30 from the collet chucks 256of the end effector 247, the presser member 266 of the end effector 247is lowered by the cylinder 262 as soon as the case gasket 30 ispositioned slightly above the handle case 4. Now, the case gasket 30 ispressed against the handle case 4 (see FIG. 19). Substantiallyconcurrent with this, the assisting jig 246 operates as follows:

The gasket holding mechanism 286 of the assisting jig 246 is movedforwardly to a predetermined position by the cylinder 284. The pressermember 288 of the gasket holding mechanism 286 is turned about the pin292 by the cylinder 290 to the portion of the case gasket 30 which isopposite to the portion thereof that is pressed by the presser member266 of the end effector 247. Thus, the case gasket 30 is reliablydisengaged from the collet chucks 256 and the protrusions 32 on thehandle case 4 are fitted respectively in the small holes in the casegasket 30. The mounting of the case gasket 30 on the handle case 4 isnow completed.

After the case gasket 30 has been set on the handle case 4 in the fifthassembling station 45, the protrusions 32 are deformed by staking in thesixth assembling station 46 to fix the case gasket 30 to the handle case4. FIG. 22 fragmentarily shows a device for fixing a case gasket.

A holder block 302 mounted on the lower distal end of a rod 300 which iscoupled to a drive source (not shown) for vertical displacement supportsa number of staking tools or punches 304 on its lower surface fordeforming the protrusions 32 on the flange surface of the handle case 4.The process of fixing the case gasket 30 to the handle case 4 iscompleted when the holder block 302 is lowered by the drive source toenable the staking tools 304 to deform the corresponding protrusions 32.

In the next seventh assembling station 47, the ends of the hinge pins8a, 8b which have been mounted on the door handle assembly 2 in thesecond and third assembling stations 42, 43 are deformed or flattened toretain these hinge pins 8a, 8b on the door handle assembly 2 againstdislodgment. This assembling step is carried out by a device shown inFIG. 23.

In FIG. 23, a hinge pin staking device 310 includes a rod 312 extendingfrom a cylinder (not shown), a horizontal beam 314 coupled to the rod312, and a pair of staking mechanisms 316, 318 mounted on the lowersurface of the horizontal beam 314 and movable horizontally toward andaway from each other. The staking mechanisms 316, 318 have motors (notshown) for moving these respective staking mechanisms horizontally, andcylinders 321, 323 for extending respective punches 320, 322 onconfronting distal ends thereof.

A backup mechanism 324 is mounted centrally on the lower surface of thehorizontal beam 314 for engaging and holding inner ends of the hingepins 8a, 8b when the other outer ends thereof are flattened respectivelyby the punches 320, 322. The backup mechanism 324 includes a bar 328disposed between and mounted on distal ends of support plates 326a,326b, and a pair of abutting members 330a, 330b slidably fitted over thebar 328. The abutting members 330a, 330b have distal ends which arenormally urged toward each other by coil springs 332a, 332b. Between theabutting members 330a, 330b, there is fitted a wedge member 334 taperedor progressively narrower toward the distal end thereof. The wedgemember 334 is movable back and forth by a cylinder 336 mounted on theupper surface of the horizontal beam 314.

When the pallet 54 arrives at the seventh assembling station 47, thehinge pin staking device 310 operates as follows: The horizontal beam314 is lowered by a non-illustrated drive source until the stakingmechanisms 316, 318 reach the position shown in FIG. 23. Then, thecylinder 336 is actuated to lower the wedge member 334 which causes theabutting members 330a, 330b to abut against the hinge pins 8a, 8b.Thereafter, the punches 320, 322 of the staking mechanisms 316, 318 areextended by the respective cylinders 321, 323 to stake the outer ends ofthe hinge pins 8a, 8b. The hinge pins 8a, 8b can be effectively stakedsince the opposite inner ends of the hinge pins 8a, 8b are backed up bythe abutting members 330a, 330b.

Subsequently, the key guard assembly 20 is mounted on the handle case 4in the eighth assembling station 48. FIG. 24 shows a device in theeighth assembling station 48 for superposing the gasket 22 and thegasket cap 24 into the key guard assembly 20.

As shown in FIG. 24, a device 340 for superposing key guard assemblycomponents includes a horizontal beam 342 extending from a base (notshown) and supporting a pair of parallel rails 344a, 344b extendinghorizontally along the beam 342. Sliders 346a, 346b slidably mountedrespectively on the rails 344a, 344b are integrally attached to a firstsupport plate 348. Confronting cylinders 349, 350 are disposed on hebeam 342, the cylinder 349 being fixed to the beam 342. The cylinder 349has a piston rod 352 coupled to the piston rod 354 of the cylinder 350which is integrally secured to the first support plate 348 by a bracket355. Therefore, the various structural components and a superposingmechanism (described later) are horizontally displaceable by thecylinders 349, 350.

To the first support plate 348, there is fixed a guide plate 356 overwhich sliders 357a, 357b integral with a second support plate 358 areslidably fitted. A superposing mechanism 364 (described later) isdisposed on the second support plate 358. An attachment plate 359 isaffixed to the upper end of the second support plate 358. A cylinder 361mounted on the attachment plate 359 has a piston rod 361a secured to thefirst support plate 348. Therefore, the second support plate 358 and thesuperposing mechanism 364 are vertically displaceable with respect tothe first support plate 348 in response to operation of the cylinder361. The superposing mechanism 364 has a body 366 slidably engaging aguide plate 360 mounted on the second support plate 358.

FIGS. 25 through 27 show the superposing mechanism 364 in detail. Thesuperposing mechanism 364 includes the body 366, and the piston rod 363of a first cylinder 362 (FIG. 24) fixed to the attachment plate 359 iscoupled to the body 366. A cylindrical member 370 is loosely fitted inthe body 366 and has an upper end connected to the piston rod 374 of asecond cylinder 372. The cylindrical member 370 has on its lower portiona tapered surface 376 which is progressively narrower in diameter in thedownward direction. The cylindrical member 370 has a hole 378 definedcoaxially therethrough, and a rod 382 connected to a third cylinder 380mounted on the cylindrical member 370 for opening and closing a colletchuck is inserted through the hole 378. The rod 382 has a lower distalend on which a collet widening member 384 with a larger-diameter portion384a on its lower distal end is coaxially mounted.

A first collet chuck 386 is mounted on the lower end of the cylindricalmember 370. A resilient ring 387 is disposed around the first colletchuck 386 for resiliently contracting the first collet chuck 386radially inwardly. The first collet chuck 386 has an inner taperedsurface 385 which is engageable by the collet widening member 384. Whenthe collet widening member 384 is downwardly displaced on and along thetapered surface 385 (FIG. 26), the first collet chuck 386 is spread oropened radially outwardly against the resiliency of the resilient ring387. The outside diameter of the lower distal end of the first colletchuck 386 is slightly smaller than the inside diameter of the gasket cap24 of the key guard assembly 20.

A second collet chuck 288 is mounted on the lower end of the body 366concentrically with the first collet chuck 386 in surrounding relationthereto. Cam rods 390a through 390d are threaded in a central portion ofthe second collet chuck 388 and have distal ends engaging the taperedsurface 376 of the cylindrical member 370. Upon relative displacement ofthe cylindrical member 370 and the body 366, the cam rods 390a through390d are brought into engagement with an outer circumferential surfaceof the cylindrical member 370 which is larger in diameter than thetapered sur face 376 to open or spread the second collet 388. Aresilient O-ring 391 is disposed around the second collet 388 fornormally contracting the same radially inwardly.

As illustrated in FIG. 24, first feed passages 392, 394 are disposedbelow the key guard superposing device 340 for supplying a gasket 22 anda gasket cap 24 from a parts feeder (not shown) to the key guardsuperposing device 340. The first feed passages 392, 394 are vibrated bya vibrator (not shown) to deliver gaskets 22 and gasket caps 24 slowlyin the direction of the arrow. A workpiece table 396 which is verticallymovable by a lifting and lower means (not shown) such as a cylinder ispositioned at the ends of the first feed passages 392, 394 for receivingthereon a gasket 22 and a gasket cap 24. A second feed passage 398 isdisposed adjacent to the workpiece table 396 for feeding a completed keyguard assembly 20 to a next process. The second feed passage 298 extendsto a position near a handling robot (FIG. 28) which will be describedbelow.

FIG. 28 shows a handling robot 400 which is identical to the handlingrobots that have been described so far except for an end effector. Thecomponents of the handling robot 400 are therefore denoted by identicalreference numerals and will not be described in detail.

FIG. 29 illustrates an end effector 402 mounted on the wrist 100 of thehandling robot 400. The end effector 402 comprises a chuck means 404 forgripping and picking up a key guard assembly 20 which has been fed alongthe second feed passage 398, and a staking means 406 for inserting thekey guard assembly 20 into a handle case 4 and staking the key guardassembly 20 fixedly on the handle case 4. FIGS. 30a and 30b show the endeffector 402 in detail.

The chuck means 404 includes a cyinder 408 having a piston rod 410 onwhich there is mounted a pusher member 412 that is tapered toward itsdistal end. The pusher member 412 is disposed near ends of holder levers414a, 414b which are openably and closably coupled to each other, foropening the other ends of the holder levers 414a, 414b. The stakingmeans 406 has a drive source 416 comprising a cylinder and a stakingtool 420 mounted on the distal end of the piston rod 418 of the cylinder416 for bending the tongues 28a, 28b of a gasket cap 24 to fix the keyguard assembly 20 to the handle case 4.

Before describing the operation of the handling robot 404 in the eighthassembling station 48 to install the key guard assembly 20, operation ofthe key guard superposing device 340 shown in FIG. 24 will be describedbelow.

In FIG. 24, gaskets 22 and gasket caps 24 are fed respectively on andalong the first feed passages 392, 394 to the workpiece table 396. Whenone gasket 22 and one gasket cap 24 reach the workpiece table 396, theworkpiece table 396 is elevated to a predetermined working position by acylinder (not shown). At this time, the superposing mechanism 394 of thekey guard superposing device 340 is positioned directly above the gasketcap 24 on the workpiece table 396.

The second cylinder 372 of the key guard superposing device 340 is thenoperated to extend its piston rod 387. As shown in FIG. 25, the firstcollet chuck 386 mounted on the lower distal end of the cylindricalmember 370 coupled to the piston rod 374 now projects out of the secondcollet 388. At this time, the cylindrical member 370 is lowered relativeto the body 366, so that the cam rods 390a through 390d are relativelymoved from the tapered portion 376 onto the larger-diameter outercircumferential surface of the cylindrical member 370. Consequently, thesecond collet chuck 388 is opened to allow the first collet chuck 386 toproject out of the second collet chuck 388.

Then, the cylinder 361 is actuated to retract the piston rod 361athereof in FIG. 24. As a result, the second support plate 358 coupled tothe cylinder 361 through the attachment plate 359 is lowered while beingguided by the guide plate 356. The superposing mechanism 364 mounted onthe second support plate 358 is therefore caused to descend forreceiving the gasket cap 24 placed on the workpiece table 396.

After the lower end of the first collet chuck 386 has been positioned inthe gasket cap 24, the rod 382 extending from the third cylinder 380 islowered to cause the larger-diameter portion 384a of the collet wideningmember 384 to slide on and along the inner tapered surface 385 of thefirst collet chuck 386 to open or spread the first colet chuck 386. As aconsequence, the gasket cap 24 is held by the first collet chuck 386.The gasket cap 24 is subsequently continuously retained by the firstcollet chuck 386.

With the gasket cap 24 held by the first collet chuck 386, the pistonrod 374 of the second cylinder 372 is retracted to elevate thecylindrical member 370, and at the same time the piston rod 363 of thefirst cylinder 362 is extended to lower the body 366 coupled to thepiston rod 363, thereby drawing the first collet chuck 386 into thesecond collet chuck 388. The piston rod 361a of the cylinder 361 isextended to ift the superposing mechanism 364 in its entirety. Then, thesuperposing mechanism 364 is displaced laterally along the beam 342 inthe direction of the arrow. More specifically, the piston rod 352 of thecylinder 349 is extended and the piston rod 354 of the cylinder 350which confronts the cylinder 349 is retracted. The superposing mechanism364 is now moved along the beam 342 into a position directly above thegasket 22 on the workpiece table 396, while being guided along the rails344a, 344b.

When the superposing mechanism 346 arrives at the position above thegasket 22, it is stopped and then displaced downwardly by the cylinder361. The cylinder 361 is shut off when the lower distal end of thesecond collet chuck 288 on the lower end of the body 366 is positionedwithin the gasket 22. Thereafter, the piston rod 374 of the secondcylinder 372 is extended to cause the cam rods 390a through 390d toslide on and along the tapered surface 376 of the cylindrical member 370to open or spread the second collet chuck 388. The gasket 22 is nowsecurely held and simultaneously spread slightly radially outwardly (seeFIG. 26). Continued extension of the piston rod 374 brings the firstcollect chuck 386 out of the second collet chuck 388 to position thegasket cap 24 held by the first collet chuck 386 in superposing relationto the gasket 22. The first cylinder 362 is operated to elevate the body366 with respect to the cylindrical member 370, whereupon the secondcollet chuck 388 is released from the gasket 22 (see FIG. 27). In thismanner, the gasket 22 and the gasket cap 24 can reliably be superposedwith respect to each other by relatively displacing the first and secondcollet chucks 386, 388 which are vertically displaceable andconcentrically arranged.

Subsequently, the superposing mechanism 364 is caused to ascend by thecylinder 361 and moved laterally along the beam 342 in the direction ofthe arrow to deliver the key guard assembly 20 held by the first colletchuck 386 to the position directly above the second feed passage 398.The superposing mechanism 364 is thereafter moved downwardly, and therod 382 coupled to the third cylinder 380 is elevated to displace thelarger-diameter portion 384a of the collet widening member 384 out ofengagement with the tapered surface 385 of the first collet chuck 386.The first collet chuck 386 is contracted radially inwardly under theresiliency of the resilient ring 387 to release the key guard assembly20, which then drops onto the second feed passage 398.

The key guard assembly 20 is supplied along the second feed passage 398to a position near the handling robot 400 (FIG. 28). The handling robot400 picks up supplied key guard assemblies 20 one at a time from the endof the second feed passage 398, and sets the picked-up key guardassembly 20 on the workpieces on the pallet 40.

As shown in FIGS. 29, 30a, and 30b, the end effector 402 on the wrist100 of the handling robot 400 holds a key guard assembly 20 as follows:The end effector 204 is lowered as a whole to move the chuck means 404toward the key guard assembly 20 positioned on the end of the secondfeed passage 398. When the lower distal ends of the holder levers 414,414b of the chuck means 404 are inserted in the key guard assembly 20,the cylinder 408 is actuated to force the pusher member 412 to spreadapart the holder levers 414a, 414b, thus firmly holding the key guardassembly 20. Then, the handling robot 400 operates to set the key guardassembly 20 on the handle case 4 on the pallet 54.

As shown in FIG. 30b, the handling robot 400 inserts the key guardassembly 20 upwardly into the handle case 4 on the pallet 54. When thekey guard assembly 20 is set in the protective member 18 of the handlecase 4, the piston rod 410 is retracted to release the holder levers414, 414b from the key guard assembly 20. The cylinder 416 of thestaking means 406 is then activated to extend the piston rod 418 tocause the staking tool 420 on the piston rod 418 to bend over thetongues 28a, 28b of the gasket cap 24, whereupon the key guard assembly20 is fixed to the handle case 4. The chuck means 404 and the stakingmeans 406 which are positioned in confronting relation to each otherallow the key guard assembly 20 to be inserted and then stakedsuccessively.

The above operation of the handling robot 400 is repeated to install keyguard assemblies 20 successively supplied from the second feed passage398 on respective handle cases 4.

The bushing 34 shown in FIG. 1 is set in place in the ninth assemblingstation 49. More specifically, the bushing 34 is inserted into the hingelever 10a of the handle 6 by a handling robot which is identical to thehandling robot 90 shown in FIG. 6. Since this process of inserting thebushing 34 into the hinge lever 10a is quite simple, it will not bedescribed in detail.

Finally, the tenth assembling station 50 will be described below. In thetenth assembling station 50, a final assembling step is effected toinsert the stoppers 16 into the handle case 4, thereby completing thedoor handle assembly 2.

The tenth assembing station 50 has an apparatus comprising a handlingrobot which is substantially the same as the handling robot shown inFIG. 5 except for an end effector, a stopper supply device 500 forsupplying stoppers 16 as workpieces to the handling robot, and a jig 502for assisting the handling robot in inserting the stoppers 16. Thestopper supply device 500 is shown in FIG. 31, and the jig 502 isillustrated in FIGS. 32 and 33.

In FIG. 31, the stopper supply device 500 is disposed on an installationplate 506 at the terminal end of a feed passage 504 extending from aparts feeder (not shown). A cylinder 508 is fixed to the lower surfaceof the installation plate 506 and has a piston rod 590 with a distal endthereof connected through a joint to sockets 510a, 510b for receivingtwo respective stoppers 16. The sockets 510a, 510b are insertedrespectively in holes defined in the terminal end of the feed passage504. After the sockets 510a, 510b have received respective stoppers 16,the sockets 510a, 510b can be vertically moved by the cylinder 508. Twoupstanding columns 512a, 512b are mounted on the upper surface of theinstallation plate 506 and support a positioning plate 514 having tworecesses defined therein. Chuck bars 516a, 516b mounted on the wrist 100of the handling robot engage in the respective recesses of thepositioning plate 514. Needles are attached to the lower distal ends ofthe chuck bars 516a , 516b for piercing and picking up the stoppers 16from the sockets 510a, 510b.

The jig 502 shown in FIG. 32 has some common parts identical to those ofthe assisting jig 246 (FIG. 20) used in the fifth assembling station 45.Only those components which are unique to the jig 502 will be describedbelow, whereas the common parts are denoted by identical referencecharacters and will not be described in detail.

A handle opening and closing mechanism 542 which is movable back andforth by a cylinder 540 includes a substantially C-shaped hand 544 forengaging opposite sides of the handle 6, and an angularly movable arm546 coupled to the hand 544. The angularly movable arm 546 is coupled tothe piston rod 548 of a cylinder 547 through a link 549. The handleopening and closing mechanism 542 also includes a stopper bolt 550 forstopping the arm 546.

The stoppers 16 are installed on the handle case 4 in the tenthassembling station 50 in the following manner.

When stoppers 16 are delivered from the non-illustrated parts feederalong the feed passage 504, as shown in FIG. 31, since the sockets 510a,510b are initially positioned slightly lower than the position of thestoppers 16 thus delivered, the stoppers 16 are fitted respectively intothe sockets 510a, 510b. At this time, the chuck bars 516a, 516b on thewrist 100 are in a standby position in engagement with the positioningplate 514, as shown in FIG. 31. As a result, by extending the piston rod509 of the cylinder 508, the sockets 510a, 510b are elevated to causethe needles on the distal ends of the chuck bars 516a, 516b to piercethe stoppers 16 received respectively in the sockets 510a, 510b. Thehandling robot is then operated to move along a learned path to installthe stoppers 16 on the handle case 4 as shown in FIG. 33. At this time,the jig 502 operates as follows:

The jig 502 is lowered from a position higher than the illustratedposition of FIG. 33 by a lifting and lowering means (not shown) to bringthe clamp release lever 278 supported on the distal ends of the arms276a, 276b into a vertical position at the lower ends of the clampingmembers 70a, 70b of the pallet 54. Then, the piston rod 280 of thecylinder 279 is retracted to pull the arms 276a, 276b to move the clamprelease lever 278 into engagement with the clamping members 70a, 70b tounclamp the handle case 4 from the clamping members 70a, 70b.Thereafter, a cylinder 540 is operated to move the handle opening andclosing mechanism 542 forwardly to cause the hand 544 to engage thehandle case 4. The piston rod 548 of the cylinder 547 is then retractedto turn the hand 544 in the direction of the arrow to open the handlecase 4. The handle case 4 still remains clamped on the pallet 54 by theclamping lever 80.

While the handle case 4 is being opened, the handling robot brings thechuck bars 516a, 516b into a desired position within the handle case 4,and installs the stoppers 16 on the handle case 4.

All the assembling steps in the assembling stations 41 through 50 arenow finished, and the completed door handle is produced.

Although a certain preferred embodiment has been shown and described, itshould be understood that many changes and modifications may be madetherein without departing from the scope of the appended claims.

What is claimed is:
 1. A method of assembling a door handle, comprisingthe steps of:clamping a handle case and a handle which are substantiallyassembled on a pallet with respective first and second clamping means onsaid pallet, said first clamping means clamping said handle casedownwardly on said pallet, said second clamping means clamping one endof said handle beneath said handle case such that another end of saidhandle to be connected to said handle case extends upwardly through saidhandle case; conveying said pallet along a looped conveyor; connectingsaid handle case and said handle operatively to each other with hingemeans in a first assembling station disposed alongside of said conveyor;and thereafter conveying said pallet successively through otherassembling stations disposed along said conveyor to install other doorhandle components on said handle case and said handle in said otherassembling stations.
 2. The method according to claim 1, wherein saidother door handle components include a stopper to be installed in one ofsaid other assembling stations, further including the steps of:releasingsaid first clamping means to unclamp said handle case while clampingsaid handle to said pallet with said second clamping means in one ofsaid other assembling stations; thereafter, turning said handle case onsaid handle in said one of the other assembling stations; and insertingthe stopper into said handle case in said one of the other assemblingstations.
 3. The method according to claim 1, wherein said hinge meanscomprises a pair of first and second coil springs and a pair of firstand second hinge pins, further including the steps of:installing saidfirst coil spring and said second hinge pin on said handle case and saidhandle in said first assembling station; and thereafter installing saidsecond coil spring and said second hinge pin on said handle case andsaid handle in a next assembling station.
 4. The method according toclaim 3, wherein the steps of installing the first and second coilsprings and the first and second hinge pins further comprise the stepsof:inserting a first guide pin into a first set of pin holes defined insaid handle case and said handle at said first assembling station, saidfirst set of pin holes receiving said first hinge pin; positioning saidfirst coil spring on said handle case and said handle; inserting saidfirst hinge pin through said first set of pin holes while simultaneouslyremoving said first guide pin therefrom; inserting a second guide pininto a second set of pin holes defined in said handle case and saidhandle at said next assembling station, said second set of pin holesreceiving said second hinge pin; positioning said second coil spring onsaid handle case and said handle; and inserting said second hinge pinthrough said second set of pin holes while simultaneously removing saidsecond guide pin therefrom.
 5. The method according to claim 4 furthercomprising:rotating said first and second guide pins while insertingsaid guide pins through said first and second sets of pin holes.